Wednesday, 28 May 2008

lung cancer...facts to remember

This is the most common malignant tumour in the West and is the third most common cause of death in the UK after heart disease and pneumonia.

In the UK, 32 000 people die each year from bronchial carcinoma, with a male-to-female ratio of 3: 1.

Non-small-cell carcinoma

1-Squamous cell carcinoma

Is the commonest type, accounting for approximately 40% of all carcinomas

Most present as obstructive lesions of the bronchus leading to infection.

It occasionally cavitates (10%) at presentation.

Local spread is common but widespread metastases occur relatively late

Produce ectopic hormones:

  • Ectopic PTH
  • Ectopic TSH
  • Other features include: HPOA, Gynaecomastia and clubbing


2-Adenocarcinoma

Adenocarcinoma accounts for approximately 10% of all carcinomas

Arises from mucous cells in the bronchial epithelium

Invasion of the pleura and the mediastinal lymph nodes is common

Metastases to the brain and bones.

Associated with asbestos and is proportionally more common in non-smokers

3-Large cell carcinomas

These account for about 25% of all lung cancers

Metastasize early


4-Bronchoalveolar cell carcinoma

Accounts for only 1-2% of lung tumours

Occurs either as a peripheral solitary nodule or as diffuse nodular lesions of multicentric origin

Occasionally this tumour is associated with expectoration of very large volumes of mucoid sputum


Small-cell carcinoma

Accounts for 20-30% of all lung cancers.

It arises from endocrine cells (Kulchitsky cells), These cells are members of the APUD system, which explains why many polypeptide hormones are secreted by these tumours.

It produces:

  • SIADH
  • Ectopic ACTH
  • Eton-Lambert syndrome

Small-cell carcinoma spreads early and is almost always inoperable at presentation

It is radiotherapy resistant but responds to chemotherapy however the prognosis remains poor.

Poor prognostic features:Na>132,wt loss>10%,performance state >2,ALP>1.5 of normal,LDH>1.5 of normal and extensive disease.

Diagnosis

  1. Bronchoscopy and biopsy/bronchial brushing (80% within the reach of the scope)
  2. Sputum cytology
  3. Per cutaneous needle biopsy
  4. CT san of chest (and head & liver for staging)

Treatment

Surgical:

85% not respectable

Contraindication to surgery:

Metastasis

Mediastinal organ invasion

Malignant pleural effusion

Contralateral mediastinal node

FEV1 <0.8 L

Severe cardiac /other conditions


Radiotherapy:

Radical especially in conjunction with chemotherapy

Palliative for SVCO


Combined chemotherapy:

Useful in small cell cancer